1 onion, minced
1 lb. ground beef
1/2 lb. American processed cheese, cut in 1/4 inch cubes
1 (8 oz.) pkg. macaroni, cooked
1 tbsp. mustard
1 can corn, drained
1/2 tsp. salt
1/4 tsp. pepper
1 can tomato soup

Brown ground beef with onions. Mix cheese, macaroni, mustard, corn, salt, pepper and tomato soup. Stir in mixture of meat and onions. Place in buttered casserole dish. Bake at 350 degrees for 1 hour.